Everyone who loves and studies animals knows that each differs from others of its species, in its habits and little ways, as distinctly as children, and men, and women are diverse in character and disposition. The horses you have owned, the dogs you have loved, your cats, parrots, and even your pet cage-birds and little white mice, have possessed widely varying characters and idiosyncrasies. Fishes, the crustacea, and even the octopods are not excepted from this individuality. The hen octopus in question, whilst on sentry duty guarding her undeveloped progeny, assumed a position and attitude totally different from that adopted by her predecessor in maternal joys. The syringing of her eggs with a current of water from the syphon tube was repeated by her; but she never cradled them, as did the other, in the expanded membrane of a limb. Her usual posture was with the under portion of her body presented to them, her eight arms turned completely back, exposing their under surface armed with their battery of suckers, the muzzles of the latter pointing in every direction, and the tip of the hard, horny beak, just discernible. The fine ends of the arms might sometimes be seen gently winding amongst the clusters of eggs as tenderly and lovingly as a father’s fingers through the tresses of a darling child, but there was no evident nursing in this case.
An octopus about to spawn, like some birds in search of a nesting-place, seeks the most retired nook she can find in which to deposit her eggs. The elasticity of her body enables her to squeeze herself through a very small orifice; and, therefore, the narrower the entry to her den the more suitable is it for her purpose, because the better adapted for defence against enemies and intruders. A curious instance of the choice of such a nesting-place came under my notice in March, 1874. Some fishermen, whilst dredging in the Channel off Brighton, brought up an earthen jar or carboy, which would hold about two gallons. It was covered with serpulæ, &c., and was forthwith taken to the Aquarium. There it was discovered that it contained an octopus and her eggs. The neck of the jar was only two inches in diameter: the octopus was a fully-grown specimen.
The young octopus fresh from the egg is of about the size of a large flea, and when irritated is of nearly the same colour. It is very different in appearance from an adult individual of the same species. At first sight it is more like a sepia, without its tentacles, than an octopus. The arms, which will afterwards be four or five times the length of its body, are so rudimentary as to be even shorter in proportion than the pedal arms of the cuttle-fish, and appear only as little conical excrescences, having points of hair-like fineness, and arranged in the form of an eight-rayed coronet around the head.
At this early stage of its existence the young octopus seeks and enjoys the light which it will, later in life, carefully shun. It manifests no desire to hide itself in crevices and recesses, as the adult does, but swims freely about in the water, often close to the surface, propelling itself backward by a series of little jerks caused by each stroke of the force pump, which expels a jet of water from the out-flow pipe of the syphon. This contrast of its habits in youth and age is so remarkable that when, after witnessing the gay activity of the movements of the child-octopus, I again watched the furtive, skulking habits of its shrivelled-skinned father, I could not help comparing the latter with the old thief-trainer in “Oliver Twist,” and wondering whether there ever could have been a time in the life of Fagin the Jew when he was innocent and frolicsome, and played, and leaped, and ran, and danced, and revelled in the sin-exposing sunshine, ere the light of day became odious to him, and he shrank from it as a danger to be dreaded, and kept himself hidden in his den whilst his emissaries went out, like the arms of the old octopus, in search of prey for the benefit of their employer.
I can say but little concerning the fertilisation of the eggs of the octopidæ in a book intended for readers of all classes, but it is so remarkable that this chapter would be incomplete without a few words upon the subject. They are fecundated before, not after, their extrusion. In the breeding season a curious alteration takes place in one of the arms of the male octopus; according to Steenstrup, always the third on the right side, although it has been stated that the third arm on the left is sometimes the one thus affected. The limb becomes swollen, and from it is developed a long, worm-like process, furnished with two longitudinal rows of suckers, from the extremity of which extends a slender, elongated filament. When its owner offers his hand in marriage to a lady octopus she accepts it, and keeps it, and walks away with it, for this singular outgrowth is then detached from the arm of her suitor, and becomes a moving creature, having separate life,[18] and continuing to exist for some time after being transferred to her keeping. In the meanwhile the lost portion of the “hectocotylized” arm of the male is gradually reproduced, and in due time it assumes its former appearance.
The habits of the Eledone, of which there is only one British species, E. cirrosa, are the same as those of Octopus vulgaris, from which it chiefly differs in having only one row of suckers instead of two along the under surface of its arms. Individuals of this species have occasionally deposited a few eggs in the Brighton Aquarium; but these have not, hitherto, arrived at maturity. They are considerably larger than those of the octopus, and not so numerous. The eledone is not so hardy as its relative, and, in captivity, the female generally dies in spawning.
It is impossible for any student or observer of these animals to avoid recognition of Aristotle’s wonderfully intimate knowledge of their life-history, embryology, sexual conditions, and anatomy. When I first saw the octopus guarding her eggs the thought immediately rose in my mind,—“Aristotle must have had an aquarium!” He might have learned by observations at the sea-side, on the coast of the Mediterranean, the mode of progress of the octopus when swimming and crawling, its change of colour when excited, the form of its eggs, &c., which he has correctly described; but it is impossible that he could have so exactly designated the duration of the existence of the embryo in the egg without having had opportunities of noticing the date of its extrusion, and that of the escape of the young octopods by the rupture of the envelope. His mention of the remarkable sexual development of one of the arms, its use in the impregnation of the ova, their apparent incubation by the mother, and her incessant attention to her charge, also indicates that, during the intervening time, the male and the brooding female were continually under his inspection. We are therefore led to the conclusion that the marine aquarium, in some form, is one of the things that are not “new under the sun.”